Is sexual fantasy about your own partner appropriate?

In my work with the LifeSTAR program, an interesting question has been brought up by men in recovery from sexual addiction. The question is, “Is it OK for me to have sexual fantasies in my mind about my own wife?”
I recognize that the question of the appropriateness of sexual fantasy is not so simple as to merit a few paragraphs only. However, in the context of individuals struggling with compulsive sexual behaviors, such sexual fantasies can be concerning.
I think that the above question actually gets at a common, but flawed, assumption about sexual intimacy in marriage. The assumption is this: once I am married to someone, “anything goes” sexually. There should be no limitations or boundaries around how I approach my spouse sexually or engage in my sexual relationship.
So what harm is there in creating mental sexual fantasies about one’s own spouse?
First, fantasy sexuality and real sexuality are not the same thing. In fantasy, you do not have to put any effort into the relationship, and sex is “free” and without the obligation of emotional engagement.
Second, in sexual fantasy, even when the subject of the fantasy is one’s own spouse, the person in the fantasy becomes objectified. In the fantasy, the spouse actually becomes a sort of sexual puppet, subject to the whims of the person creating the fantasy. This is the opposite of how real relationships should work.
Fantasizing about one’s own spouse creates a false version of that person that the real person cannot, nor ever should, try to live up to. The fantasy person is not human, does not have emotions, cannot say “no,” and does not require any real relational engagement.
Thus, the sexual fantasy actually works against marital intimacy instead of enhancing it. It is no different than the fantasy of pornography, in which real intimacy is replaced by a distortion—except that the individual objectified in the fantasy is one’s spouse. The end result is the same: trauma, shame, relational maladjustment, and emotional pain.
The way out of this trap is to learn to make real relational, emotional, and sexual connections with your partner and abandon the fantasies that undermine these efforts.